Energy transmission apparatus

ABSTRACT

Energy transmission apparatus for controlling neonate body temperature consisting of a support platform for infant support, a heat source in proximity to the platform, energy guides surrounding the platform which transmit and guide heat energy from the heat source to the platform, and a heat control for controlling changes of the heat source in accordance with body temperature changes of the neonate in order to maintain the body temperature constant.

United States Patent Franzel 154] ENERGY TRANSMISSION APPARATUS [72]Inventor: Irwin H. 'Franzel, 501 Linwood Drive, Fort Lee, NJ. 07024 221Filed: Nov. 10, 1969 21 App1.No .:875,018

521 U.s. Cl. ..128/399, 128/1 B, 350/96,

, 1 219/385 [51] Int.Cl. ..L ..A6lb19/00 [58] Field of'Search ..128/l',399, 395; 119/39, 37,

[56] References Cited UNITED STATES PATENTS 2,914,647 11/1959 Ganske eta1. ..219/349 3,299,253

1/1967 Lawson ..l.'19/37 [15] 3,698,397 [4 1 Oct. 17,- 1972 3,338,2338/1967 (irosholz et a1. ..128/1 B Sutton ..2l9/347 PrimaryExaminer-Richard A. Gaudet Assistant Examiner-.1 C. McGowanAttorney-William V. Pesce [571 ABSTRACT- Energy transmission apparatus'for controlling neonate body temperature consisting of a supportplatform for infant support, a heat source in proximity to the platform,energy guides surrounding the platform which transmit and guide heatenergy from the heat source to the platform, and a heat control forcontrolling changes of the heat source in accordance with bodytemperature changes of the neonate in order to maintain the bodytemperature constant.

6 Claims, 7 Drawing Figures PATENTEDnmmszz 3698.397

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ENERGY TRANSMISSION APPARATUS In a hospital environment where newborninfants are confined, especially those undergoing surgery, the survivalprobability of such infants, especially of premature and sick newborns,has been enhanced in recent years by the maintenance of these infants ina zone of thermal neutrality, (i.e., a temperature at which oxygenconsumption is a minimum).

Tiny and sick infants are unable to support a normal temperature in athermally hostile environment. There is a definite degree of heat lossby premature neonates, and unless-such heat loss is compensated for bysome external source, severe metabolic demands will be made on theinfant which he cannot sustain or meet, and his overall conditionrapidly deteriorates to the extent that his chances for survival becomesuspect and brain damage would ensue. The primary concern of thisapplication is the development of apparatus that will maintain theneonate in the neutral zone (optimum body temperature .of the infant)during surgical procedures. It is a fact that in most cases undersurgical conditions that hemeothermia problems are enhanced by theanesthetic suppression of the thermo regulatory mechanism of the body.It is absolutely necessary to replace the infants heat loss when suchlosses occur during clinical, nursery and surgical situationsaforementioned. Further, by the use of controlled and directed heattoward the neonate, it is possible to maintain satisfactory andcomfortable temperatures for the hospital staff, particularly in theoperating room.

It is therefore a primary object of the invention to provide a systemfor maintaining a neonate at a temperature that is in the zone ofthermal neutrality.

Another object of the invention is to provide a temperature controlsystem which automatically replaces heat loss of a neonate in asurgical, nursery and clinical atmosphere.

Another object of the invention is to providea controlled heat sourcesystem for neonates which in a surgical, clinical and nursery atmospheremay be selectively directed toward the neonate to substantially controlits body temperature in a selective area.

Another object of the invention is to provide a selfcompensating heatcontrol system for neonates in a clinical atmosphere which compensatesfor heat loss in one area by adding heat in another area.

Another object of the invention is to provide flexible means oftransmitting energy and the control thereof through a fiber opticssystem.

A still further object of the invention is to provide energy guideflexible tubular members having highly polished internal reflectivesurfaces for the transmis sion of radiant energy.

Other objects and advantages will become apparent from a reading of thespecifications and a study of the accompanying drawings in which:

FIG. 1 is a diagrammatic configuration of a neonate heat control systemaccording to the invention;

FIG. 2 is a diagrammatic view of a fiber optic transmitter capable oftransmitting light energy illustrate for instructive purposes;

FIGS. 3 and 30 show partially sectionalized a hollow goose-neck energytransmission guide consisting of helically wrapped interlocking stripswith the interior coated with a highly polished and reflective materialsuch as gold;

FIGS. 4 and 4a show an energy guide composed of an assembly of finelydrawn flexible fibers of an infra-red transmissive medium such asarsenic tri-sulfide;

FIG. 5 shows a detailed configuration of a schematic diagram showing oneembodiment of a circuit for controlling radiant energy according to theinvention.

Now describing the invention with respect to its various FIGURES anddesignating those elements with the same reference numbers when thefunctions. are the same or similar, there is shown in FIG. 1 adiagrammatic drawing embodying the invention and comprising asupportable table or platform 1 disposed and having reposed thereon aneonate (not shown) capable of being kept at a constant bodytemperature, said temperature of the neonate being maintained atapproximately 36 centigrade by the novel means herein described.

Below the table or platform 1, a source of radiant energy 2, disposed togive off energy in the form of infra-red radiation,is suitably placedand modulated by a servo-amplifier 3 having a sensing input 4 inproximity to the aforementioned neonate for monitoring his temperatureand controlling the servoamplifier output accordingly. Flexible energyguides, such as fiber optic members 6, are conveniently placed about theedges of the table 5, the bottom portions of said members being placedin spaced-proximity to the infra-red source 2 and the upper portiondepending and directed toward said neonate in spaced proximity thereto.Reflectors 8 direct and focus the desired radiant energy into the energyguides. The fiber members 6 are each capable of receiving radiant orinfra-red energy from the energy source 2, including the reflectors 8,atom end and capable of transmitting said energy to the other end inaccordance with well-known fiber optics principles.

For example, merely by way of explanation, there is shown in FIG. 2 afiber optic tube 10 for transmitting energy and composed of a fiber core11 and surrounding cladding 12. It may be described as a core of glasssurrounded by another glass which has a lower index of refraction. Thefiber traps light energy within a defined critical angle a and, due tototal internal reflection, transmits this light energy down the fiber tobe emitted from the output at the same angle as it entered. The lightenergy is not transmitted through the cladding because the angle ofincidence on the walls is greater than the critical angle b necessaryfor total reflection. The critical angle and the numerical aperture ofthe fiber will depend on the refractive indices of the two glasses. Thenumerical aperture (NA) defines the maximum acceptance angle at whichthe fiber can trap and reflect 1i ht energy. The relationship NA sin a='1, n2 l ililiflfl flz. ar he. retrastiveiud ps 9 the two glasses, withincident ray travelling in air.

The fiber optic energy guides can be assembled in a flexible metallicorplastic tubing of such a nature that the output ends may be positionedand aimed at whatever portion of the platform or neonate desired.Helically wrapped goose-necked tubing provides the flexi-' bility foraiming the radiant energy while it has the structural rigidity tomaintain its position without any other support; Visible radiation maybe incorporated in the spectral output of the energy sources in order toprovide the means for observing the area irradiated by the thermalenergy to permit optimum distribution of the energy to the neonate andsurgical fields.

FIG. 1 further shows an optical filter 7' disposed to be placed betweenthe heat source and energy guides to filter out light which mightotherwise interfere with the surgeon 's view of the operative field.

An alternate energy guide configuration, shown in FIG. 3, consists of ahollow metallic goose-neck l comprised of helically-wrapped interlockingstrips 16 with the interior gold-plated to enhance the infra-redreflection. In procedures other than neonatal thermoregulatory systems,the hollow energy guide could be significantly more efficient than thefiber optic guides. Application of this invention to the controlled andrapid warming of surgical fields whose temperature has been depressedfor medical purposes, such as openheart surgery, could advantageouslyuse the hollow energy guide technique.

A further energy guide configuration is shown in FIG. 4 and comprises anassembly of finely drawn, flexible fibers 17 of an infra-redtransmissive medium such as, for example, arsenic trisulfide. These,too, would be incorporated into a goose-neck tube for positioning andaiming. Although the decomposition products of the former might betoxic, and economic considerations might preclude the use of silverin'comparison to the other techniques described above, specificapplications might indicate significant advantages of one form of energyguide over the others.

There is shown in FIG. 5 a representative circuit for providing powerand controlling the heat source. In particular it is comprised of an acvoltage source 18 connected to a full-wave bridge rectifier array 19containing rectifier elements 20a, 20b, 20c, 20d, be they electron tubesor solid-state diodes. The bridge output is connected to a resistiveelement or heater 21. The heater may take on the form of infra-redlamps, glowheaters, and the like, so as to produce the necessary radiantenergy.

The bridge 19 has connected thereto a solid state semiconductor controldevice and amplifier 22 having a sensor device or probe 23 suitablyconnected and disposed to change its resistive value to permit a changein the bias conditions of said amplifier so as to affect a change in theduty cycle of the current being conducted. For example, for some part ofone-half cycle of the voltage source, current flows through rectifier20a, servo-amplifier 22 and rectifier 20c to the output load 21. On thereverse cycle, current flows from voltage source through rectifier 20b,servo-amplifier 22, in same direction as previously and, finally,through 20d and again to the external load. Hence, any change in theprobe resistance-changes the current flow to the output load circuit.

The external sensor or probe is generally placed in the feed-backcontrol system, the temperature change or heat loss would be compensatedfor by an increased output from the other guides. Hence, it IS possibleto increase or decrease the number of guides without any degradation ofthe thermal control system.

The invention herein presented provides means for the transmission andcontrol of energy through fiber optic energy guides and in a broadersense has applications in industrial process control by permittingenergy to be directed to areas that have to be precisely controlled.

While the invention has been described and illustrated with respect to acertain particular preferred embodiment which gives satisfactoryresults, it will be understood by those skilled in the art, afterunderstanding the principle of the invention, that various changes andmodifications may be made without departing from the spirit and scope ofthe invention, and it is intended,

changes and modifications.

Having defined the invention, what is claimed is: g

1. Energy transmission apparatus for controlling neonate bodytemperature changes comprising, a support platform for supporting saidneonate, a heat source in proximity to said platform, fiber opticmembers composed of optical fibers in proximity to said platform andheat source, and disposed to receive and transfer heat from said sourceto said platform, and control means including a sensor interposed saidplatform and heat source, and disposed to control heat generated fromsaid source in response to temperature changes sensed by said sensor tomaintain constant body temperature of said neonate.

2. Energy transmission apparatus according to claim 1 and furtherincluding-reflectors in proximity to said fiber optic members forreflecting energy from said heat source to said fiber optic members.

3. Energy transmission apparatus for controlling neonate bodytemperature changes comprising a support platform for supporting saidneonate, a heat source in proximity to said platform, energy guide meansin proximity to said platform and heat source, said energy guide meansincluding tubular flexible guides, and disposed to receive and transferheat from said source to said platform, and control means including asensor interposed said platform and heat source, and disposed to controlheat generated from said source in response to temperature changessensed by said sensor to maintain constant body temperature of saidneonate.

4. Energy transmission apparatus according to claim 3 and wherein saidtubular flexible guides are composed of helically wrapped interlockinggold plated strips configured to provide flexibility and enhance energyreflection.

5. Energy transmission apparatus according to claim 3 and wherein saidtubular flexible guides have internal arsenic tri-sulphide flexiblefibers.

6. Energy transmission apparatus according to claim 3 and wherein saidenergy guide means further include reflectors for reflecting energy fromsaid heat source to said tubular flexible guides.

1. Energy transmission apparatus for controlling neonate bodytemperature changes comprising, a support platform for supporting saidneonate, a heat source in proximity to said platform, fiber opticmembers composed of optical fibers in proximity to said platform andheat source, and disposed to receive and transfer heat from said sourceto said platform, and control means including a sensor interposed saidplatform and heat source, and disposed to control heat generated fromsaid source in response to temperature changes sensed by said sensor tomaintain constant body temperature of said neonate.
 2. Energytransmission apparatus according to claim 1 and further includingreflectors in proximity to said fiber optic members for reflectingenergy from said heat source to said fiber optic members.
 3. Energytransmission apparatus for controlling neonate body temperature changescomprising a support platform for supporting said neonate, a heat sourcein proximity to said platform, energy guide means in proximity to saidplatform and heat source, said energy guide means including tubularflexible guides, and disposed to receive and transfer heat from saidsource to said platform, and control means including a sensor interposedsaid platform and heat source, and disposed to control heat generatedfrom said source in response to temperature changes sensed by saidsensor to maintain constant body temperature of said neonate.
 4. Energytransmission apparatus according to claim 3 and wherein said tubularflexible guides are composed of helically wrapped interlocking goldplated strips configured to provide flexibility and enhance energyreflection.
 5. Energy transmission apparatus according to claim 3 andwherein said tubular flexible guides have internal arsenic tri-sulphideflexible fibers.
 6. Energy transmission apparatus according to claim 3and wherein said energy guide means further include reflectors forreflecting energy from said heat source to said tubular flexible guides.